GAP JUNCTION CHANNELS IN THE CARDIOVASCULAR-SYSTEM - PHARMACOLOGICAL AND PHYSIOLOGICAL MODULATION

Intercellular communication provides the basis for the inta ct functio ning of tissue and for various organs and tissue types in an organism to work together. It is the crucial difference between isolated cells and intact tissue. Cells communicate in various ways with each other; these include the release of chemical transmitters, hormones and media tors as well as direct electrical and chemical intercellular communica tion via gap junction channels. The gap junction coupling is important for the organization of the tissue as an electrical syncytium and for accurate development. Pharmacological modulation of these channels co uld be important in the fields of arrhythmogenesis, vasomotion and cel l differentiation. In this review, Stefan Dhein outlines the structure , synthesis and function of gap junction channels. Since their physiol ogy and pharmacology are best investigated in the cardiovascular syste m, the second part of the article focuses on the role of gap junctions in the heart and vasculature, with special emphasis on the regulation of the channels by physiological stimuli such as ions, pH mediators a nd transjunctional voltage as well as their pharmacological modulation .